Another doctor from Sierra Leone who has tested positive for Ebola will be evacuated for medical treatment, an official said Thursday, making her the first citizen of a hard-hit country to be treated abroad.

Dr. Olivette Buck is the fourth Sierra Leonean doctor to contract the disease - and the three others all have died. Arrangements are being made to send her to another country for better treatment, said Health Ministry spokesman Sidie Yahya Tunis without specifying further.

So far, only foreign health and aid workers have been evacuated abroad for treatment from Sierra Leone and Liberia. The worst Ebola outbreak in history also has hit Guinea, Nigeria and Senegal, and has been blamed for more than 2,200 deaths across West Africa.

The disease is taking a particularly heavy toll on health care workers, whose jobs put them at high risk because Ebola is only transmitted through contact with the bodily fluids of people showing symptoms or dead bodies. More than 135 health workers have died in the outbreak so far, exacerbating shortages of doctors and nurses in countries that already had too few medical workers to begin with.

Sierra Leone and Liberia have been especially hard hit, and officials have warned that both countries could see a surge in cases soon. Sierra Leone is expecting to uncover potentially hundreds of new cases when volunteers go house to house looking for the sick during a three-day lockdown later this month. The World Health Organization has said Liberia could see many thousands of new cases in the coming weeks.

To keep up with the accelerating infection rate, Liberian Information Minister Lewis Brown told a news conference Thursday that the capital region alone needs 1,000 beds.

That squares with a World Health Organization estimate from earlier this week. The U.N. health agency said the county where Monrovia is located currently has only 240 beds, with 260 more on the way - only half of what's needed.

The tremendous fear surrounding the disease and the extreme measures used to contain it - like the cordoning off of entire towns for days - has led to sharp criticism of Liberia's government and even calls for the president to step down. But Brown urged Liberians to unite, warning that if they didn't, "this virus will consume all of us."

"We are at war with an enemy that we don't see," Finance Minister Amara Konneh told reporters. "And we have to win the war."

But he said Liberia would be dependent on international assistance to do so. The U.N. has said at least $600 million is needed to fight Ebola in West Africa, and already several pledges have come in. The United States has spent $100 million so far, with more promised, and Britain has given $40 million.

On Thursday, Cuba's health minister was meeting with the World Health Organization's director to discuss how it could help. Cuba has a relatively advanced medical education system and for decades has dispatched thousands of doctors to the world's developing countries. There were no details on what help it would be providing, but experts say the outbreak is desperately short of health care workers.

Konneh, the finance minister, also told The Associated Press in an interview that the outbreak has ravaged Liberia's already fragile economy, and the government predicts the crisis will more than halve the growth rate this year. He added that the government also hopes the international community will help rebuild Liberia after the crisis passes.

An unrelated Ebola outbreak in Congo is thought to have killed 35 people of the more than 60 sickened, according to the World Health Organization.